/* ----------------------------------------------------------------------
* Copyright (C) 2010 ARM Limited. All rights reserved.
*
* $Date:        15. February 2012
* $Revision: 	V1.1.0
*
* Project: 	    CMSIS DSP Library
* Title:		arm_cmplx_mag_q31.c
*
* Description:	Q31 complex magnitude
*
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*
* Version 1.1.0 2012/02/15
*    Updated with more optimizations, bug fixes and minor API changes.
*
* Version 1.0.10 2011/7/15
*    Big Endian support added and Merged M0 and M3/M4 Source code.
*
* Version 1.0.3 2010/11/29
*    Re-organized the CMSIS folders and updated documentation.
*
* Version 1.0.2 2010/11/11
*    Documentation updated.
*
* Version 1.0.1 2010/10/05
*    Production release and review comments incorporated.
*
* Version 1.0.0 2010/09/20
*    Production release and review comments incorporated.
* ---------------------------------------------------------------------------- */

#include "arm_math.h"

/**
 * @ingroup groupCmplxMath
 */

/**
 * @addtogroup cmplx_mag
 * @{
 */

/**
 * @brief  Q31 complex magnitude
 * @param  *pSrc points to the complex input vector
 * @param  *pDst points to the real output vector
 * @param  numSamples number of complex samples in the input vector
 * @return none.
 *
 * <b>Scaling and Overflow Behavior:</b>
 * \par
 * The function implements 1.31 by 1.31 multiplications and finally output is converted into 2.30 format.
 * Input down scaling is not required.
 */

void arm_cmplx_mag_q31(
    q31_t* pSrc,
    q31_t* pDst,
    uint32_t numSamples)
{
	q31_t real, imag;                              /* Temporary variables to hold input values */
	q31_t acc0, acc1;                              /* Accumulators */
	uint32_t blkCnt;                               /* loop counter */

#ifndef ARM_MATH_CM0

	/* Run the below code for Cortex-M4 and Cortex-M3 */
	q31_t real1, real2, imag1, imag2;              /* Temporary variables to hold input values */
	q31_t out1, out2, out3, out4;                  /* Accumulators */
	q63_t mul1, mul2, mul3, mul4;                  /* Temporary variables */


	/*loop Unrolling */
	blkCnt = numSamples >> 2u;

	/* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
	 ** a second loop below computes the remaining 1 to 3 samples. */
	while(blkCnt > 0u) {
		/* read complex input from source buffer */
		real1 = pSrc[0];
		imag1 = pSrc[1];
		real2 = pSrc[2];
		imag2 = pSrc[3];

		/* calculate power of input values */
		mul1 = (q63_t) real1 * real1;
		mul2 = (q63_t) imag1 * imag1;
		mul3 = (q63_t) real2 * real2;
		mul4 = (q63_t) imag2 * imag2;

		/* get the result to 3.29 format */
		out1 = (q31_t)(mul1 >> 33);
		out2 = (q31_t)(mul2 >> 33);
		out3 = (q31_t)(mul3 >> 33);
		out4 = (q31_t)(mul4 >> 33);

		/* add real and imaginary accumulators */
		out1 = out1 + out2;
		out3 = out3 + out4;

		/* read complex input from source buffer */
		real1 = pSrc[4];
		imag1 = pSrc[5];
		real2 = pSrc[6];
		imag2 = pSrc[7];

		/* calculate square root */
		arm_sqrt_q31(out1, &pDst[0]);

		/* calculate power of input values */
		mul1 = (q63_t) real1 * real1;

		/* calculate square root */
		arm_sqrt_q31(out3, &pDst[1]);

		/* calculate power of input values */
		mul2 = (q63_t) imag1 * imag1;
		mul3 = (q63_t) real2 * real2;
		mul4 = (q63_t) imag2 * imag2;

		/* get the result to 3.29 format */
		out1 = (q31_t)(mul1 >> 33);
		out2 = (q31_t)(mul2 >> 33);
		out3 = (q31_t)(mul3 >> 33);
		out4 = (q31_t)(mul4 >> 33);

		/* add real and imaginary accumulators */
		out1 = out1 + out2;
		out3 = out3 + out4;

		/* calculate square root */
		arm_sqrt_q31(out1, &pDst[2]);

		/* increment destination by 8 to process next samples */
		pSrc += 8u;

		/* calculate square root */
		arm_sqrt_q31(out3, &pDst[3]);

		/* increment destination by 4 to process next samples */
		pDst += 4u;

		/* Decrement the loop counter */
		blkCnt--;
	}

	/* If the numSamples is not a multiple of 4, compute any remaining output samples here.
	 ** No loop unrolling is used. */
	blkCnt = numSamples % 0x4u;

#else

	/* Run the below code for Cortex-M0 */
	blkCnt = numSamples;

#endif /* #ifndef ARM_MATH_CM0 */

	while(blkCnt > 0u) {
		/* C[0] = sqrt(A[0] * A[0] + A[1] * A[1]) */
		real = *pSrc++;
		imag = *pSrc++;
		acc0 = (q31_t)(((q63_t) real * real) >> 33);
		acc1 = (q31_t)(((q63_t) imag * imag) >> 33);
		/* store the result in 2.30 format in the destination buffer. */
		arm_sqrt_q31(acc0 + acc1, pDst++);

		/* Decrement the loop counter */
		blkCnt--;
	}
}

/**
 * @} end of cmplx_mag group
 */
